Tilting mechanism for venetian blinds



Oct. 30, 1945. R. c. LARSON I: 2,388,000

TILTING MECHANISM FOR VENE'IIAN BLIND S Filed Dec. 13, 1944 fiIVE/VTOE. 08527- C LAeso/v, By

Patented Oct. 30, 1945 U ED STATE S PATENT OFFICE H i 2',sss,000 y l TILTING MECHANISM FOR VENETIAN BLINDS Robert C. Larson, Los Angcles Calif.

' Application December 13, 1944, Serial No. 567,954

13 Claims. (o1. 1 -476) My invention relates to Venetian blinds and has particular preference to means forreadily controlling the angle to which the slats of the Venetian blind may be set. I r1-thepres'ent constructions of Venetian blinds T "the slats are suspended uponwebs which extend infront of andin the rear of the slats, the upper ends of the webs being secured to a tilting bar which is adapted to be rotated to raise .one of the webs and lower the other to thereby simultaneously move all of the slats to a desired angularposition; Themechanism for rotating the tilting bar is ordinarily a worm gear'mounted upon one end of the tilting bar engaged with a worm which extends transversely of the bar and is provided with a pulley, over which a cord is looped so that by pulling upon one end of the cord the tilting bar is tilted in one direction while pulling upon the other of the cords tilts the bar in the opposite direction.

One of the disadvantages of this form of operating mechanism lies in the fact that in order to prevent undue wear upon the cord and to insure the motion of the tilting bar to the desired position it is necessary to grasp both cords and to hold them both taut during the tilting operation.

It is therefore an object of my invention to provide a tilting mechanism which is normally urged to move the bar to a position closing the slats upon each other and to provide a single cord,

which is pulled to move the slats to any desired open position.

Another object of my invention is to provide a tilting mechanism of the character set forth wherein a spring is employed to urge the tilting bar to slat closing position, wherein the spring may be restrained in any desired slat opening position.

Other objects and advantages of my invention will be apparent from a study of the following specifications, read in connection with the accompanying drawing, wherein Fig. l is a fragmentary elevational View of a Venetian blind illustrating my tilting mechanism;

Fig. 2 is a vertical sectional view taken along line IIII of Fig. 1;

Fig. 3 is a vertical sectional view taken along line III-III of Fig. 1; and

Fig. 4 is a transverse vertical sectional view taken along line IVIV of Fig. 3.

Referring to the drawing, I have illustrated a typical Venetian blind as comprising a head rail 1 which is secured to the top rail of a window frame and from which the tilting bar 2 is suspended by means of suitable brackets, one of which is indicated at 3. The Venetian blind slats 4 are suspended from the tilting bar by means of webs 5, the slats being raised or lowered by means of the usual elevating cord 6.

As is ordinarily the practice, the tilting bar 2 is rotatably supported in its brackets so as to permit its rotation to raise and lower the webs 5 to tilt the slats from an extreme closed position in one direction through various open positions to tion. l

In the form of my invention illustrated herein, the operating mechanism for rotating the tilting bar 2 is shown as adapted for use with the present types of Worm and worm gear tilting mechanisms, the tilting bar 2 being provided at its end with a metal end piece I having a longitudinally extending projection 8 which is square in cross section and passes through a washer 9 rotatably mounted in the bracket 3. The bracket 3 comprises a housing within which is located a worm gear l0 having an axial opening which is square in cross section to fit upon the squared cross section of the projection 8. The bracket also constitutes a housing in which a worm ll mounted upon a cross shaft I2 is rotatably mounted, the worm ll meshing with the gear I0 so that rotation of the shaft l2 will cause the gear ID to be rotated and to thereby move the tilting bar to is various positions.

The shaft l2 extends through a bearing plate l3 stationarily mounted upon the bracket 3 and is preferably formed with a squared cross section extension l4 threaded as indicated at l5 to receive a nut I6. The bearing plate 13 has an axially extending boss IT, to the exterior surface of which is secured one end of a spring l8, the opposite nd of the spring being secured as indicated at [9 to a bracket 20, on the interior surface of a cupan extremeclosed position in the opposite direclike housing or drum 2|, the end wal1 22 of which is formed with asquared aperture through which the squared end M of the shaft I2 extends. A circular plate 23, likewise formed with a squared central aperture, is secured against the wall 22 of the drum, projecting beyond the periphery of the drum to form an end flange at one end of the cylindrical surface of the drum, the inner edge of the drum being flanged outwardly as indicated at 24 to form a radial flange at that end of the drum. The drum and its end plate 13 may be assembled and secured together in an suitable manner as a unit or the entire assembly may be maintained in place by means of the nut l6 interposition of the gearing I0 and II.

threaded upon the squared extension [4 of the shaft l2.

The exterior surface of the drum 2| has one end of a pull cord 25 secured thereto, as indicated at 26, the cord being wrapped several times about the drum while the opposite end of the cord extends downwardly along the window frame where it may be readily grasped by the user of the blind.

The spring [8 normally tends to rotate the worm in a direction necessary tojtil't the tilting bar 2 to 'a'position to tightly close the slats one upon the other while the pull cord 25 when pulled down moves the tilting bar against the force "of the spring, any suitable mechanism "being em- "ployed to hold the cord 25 in any position of adjustment. One such securing means is illustrated in Fig. l as comprising a strap of metal 26 secured to one of the vertical rails ofthe window frame so that the pull cord 2-5 may be pressed between the strap 26 and the window frame and there be frictionally held in the. position to which it has been adjusted. I

While for purposes of simplicity of illustration herein I have shown the spring asoperating the cross shaft l2, it will beapparent to those skilled in. this art that the spring may be mounted to act directly upon the extension 8 without the WhileI have shown and described the preferred embodiment of my invention, I do not desire to be limited to any of the details of construction shown and described herein, except as defined in the appended claims.

p v I claim: 1 v

"1. In a tilting mechanism for Venetian blinds,

a tilting "bar suspendingthe 'slats for rotational V" movement between a closed positionand an open "osition, a drum about which several coils of a pull cord may be wrapped, a pull cord having one *of its ends secured to said drum and extending about said drum, means interconnecting said drum'arrd said tilting bar for rotating the tilt ing bar as said drum is rotated by a pull on said pull cord, and spring means'normally urging said drum for rotation in the opposite direction.

3. In a tilting mechanism for Venetian blinds,

a tilting bar suspending the slats for rotational movement between a closed position and an open position, a drum about which several coils of a pull cord may be wrapped, a pull cord having one of its ends secured to said drum and extending about said drum, means interconnecting said drum and said tilting bar for rotating the tilting bar as said drum is rotated by a pull on said pull cord, spring meansnormally urging said drum for rotation in the opposite direction, and means for securing said pull cord at any adjusted position to hold said tilting bar against movement,

under the influence of said spring.

ROBERT C. LARSON. 

